Three Main Cost Reduction Ideas For BC Solar Cells

The current BC Solar cells is still in a relatively early stage, and the cost is still facing certain challenges, mainly from the three aspects of silver consumption, yield, and equipment cost in the BC cells link.

Since the BC cells electrode is on the back, the carrier needs to pass through the entire battery cell to reach the electrode, resulting in a relatively high internal resistance of the BC cells. In order to reduce the resistance, it is necessary to increase the amount of silver paste to thicken the silver grid line, thereby improving the battery conductivity. Referring to PV infolink data, the current BC cells silver consumption is about 13mg/W, which is 2-3mg/W higher than the TOPCon cells. In the future, by introducing OBB technology on the back of the BC cells, the silver consumption of BC cells is expected to decrease.

Since the back electrode forked electrode requires 2-3 laser grooving processes, the equipment stability and process maturity level are required to be high. The leakage problem caused by laser grooving is an important bottleneck restricting the production yield of BC cells cells. At the same time, since the back electrodes are crossed, the design of the solder strip, the welding process and the packaging process also need to be adjusted accordingly, which will affect the yield of the BC cells. The yield rate of mainstream TOPCon cells manufacturers has reached more than 99%, while the yield rate of BC cells is still around 95%.

Compared with TOPCon, the finger-shaped electrodes on the back of BC cells require additional laser slotting equipment and metallization equipment, and the precision requirements are relatively high. In addition, the current BC cells technology is not yet fully mature, and the localization and scale-up of related equipment cost reduction are not sufficient. Therefore, the current BC cells single GW capital expenditure is relatively high, about 300 million yuan/GW.